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IAUC 7037: N Sco 1998; 1998eg

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                                                 Circular No. 7037
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)


NOVA SCORPII 1998
     W. Liller, Vina del Mar, Chile, writes:  "A low-resolution CCD
spectrogram obtained on Oct. 23.04 UT with a 0.20-m Schmidt camera
(+ objective prism) shows a broad, intense H-alpha emission line at
a level about 7.6 times brighter than the surrounding continuum.
This strong emission explains why the visually determined
magnitudes are fainter (by roughly a magnitude) than those obtained
with a CCD.  On Oct. 23.003, I measured the magnitude with a CCD (+
a minus-infrared filter) to be 7.78."
     M. Fujii, Kurashiki, Okayama, Japan, reports that
spectroscopic observations (0.28-m reflector; resolution about 1
nm; instrumental resolution about 450 km/s) on Oct. 24.42 UT show
strong, broad H-alpha emission (FWHM about 3800 km/s and strong,
broad H-beta emission.  The spectrum can be seen at
http://www1.harenet.ne.jp/~aikow/n_sco1998.gif.
     Visual magnitude estimates:  Oct. 22.756 UT, 8.6 (B. Monard,
Pretoria, South Africa); 22.91, 8.7 (J. G. de S. Aguiar, Campinas,
S.P., Brazil); 23.41, 8.5 (A. Jones, Nelson, New Zealand); 23.912,
8.9 (Aguiar); 24.04, 9.0 (W. G. Dillon, Missouri City, TX).


SUPERNOVA 1998eg IN UGC 12133
     M. Salvo, A. Pastorello, L. Rizzi, and V. Buondi, Asiago
Astrophysical Observatory, report that inspection of a preliminary
spectrum (range 380-700 nm) obtained on Oct. 20.45 UT with the
1.82-m telescope (+ AFOSC) shows that SN 1998eg (V about 17.4) is a
type-Ia supernova soon after maximum.  The spectrum shows the
635.5-nm absorption of Si II typical of type-Ia supernovae.  Given
the redshift of the parent galaxy (7500 km/s), the expansion
velocity deduced from the minimum of Si II (635.5 nm) is about
10 500 km/s.
     S. Jha, P. Garnavich, P. Challis, and R. Kirshner, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN
1998eg was obtained by P. Berlind on Oct. 24.1 UT with the F. L.
Whipple Observatory 1.5-m telescope (+ FAST spectrograph), showing
it to be a type-Ia supernova near maximum brightness.  The age
determined from a fit to the observed spectral features (Riess et
al. 1997, A.J. 114, 722) is 1 +/- 2 days after maximum light.  The
spectrum also exhibits redshifted narrow interstellar Na I D lines,
implying significant extinction by dust in the host galaxy and
yielding a recession velocity for the host galaxy of 7400 km/s.
The expansion velocity of the supernova is 10 200 km/s, measured
using the prominent Si II (rest 635.5 nm) feature.

                      (C) Copyright 1998 CBAT
1998 October 24                (7037)            Daniel W. E. Green

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